Body to be heated electrically.



PATENTED MABm 12. 1907.

.1 E.HAAGN. BODY TO BE HEATED ELEGTRIGALLY.

APPLIUATION FILED MAR. 16, 1906.

ERNST HAAGN, or HANAU,

GERMANY, ASSIGNQR TO THE FIRM OF C.

HERAEUS, or HANAU, GERMANY.

BODY To BE HEATED ELECTRICALLY.

Specification of Letters Patent. 1 Patented March 12, 1907.

Applicat ion'filed March 16.1906. Serial No. 306,437.

To (1, whom it may concern:

Be it known that I, ERNST HAAGN, a subject of the German Emperor, and a-res-ident of Hanau, Germany, have invented certain new and useful Improvements'in Bodies to be Heated Electrically, of which the followthe heavy ing is a specification.

Crucibles, boxes, muffics,,'plates, and other bodies adapted to be heated electrically are, known in which the resistances are embedded in the walls. To insure a unif orr'n load of the resistances, and thereby to lengthen the life of the said bodies, it is necessary that the resistances should be united with the body as carefully and as reliably as possible. This, however, can be effected only with difliculty, more particularly in case the bodies are small and the resistances require to be made of wire in view of the usual pressures of the current. In some cases'this was effected in the manner that the wire was spirally wound on a tube of porcelain, fire-clay, or other fireproof material by means of a lathe, .or it was placed in a spiral groove on the tube, after which a paste was applied to the wire-00v} ered surface and then-the whole body was enameled. In other cases the wire was spirally wound, was introduced intoa tube and a paste was applied to the inside of .the latter to cover the wire. Both methods presented, however,

defect that during-the burning operation the paste will contract much more than-the tube and istherefore liable to tearing or getting fractured, and in anycase it will bug imperfectly unite with the wires and the tu e.

ble if the wire employed be very thick, which,

- however, cannot be employed particularly. in

case of platinum wire'onaccount of the high 1 latinum. Both methods are price of the quite useless plates, muflies, and boxes were to be providedwithwires embedded in them.

. A third method, described in *theQUnited wire -is spirally Wound on a core and a paste is applied to the outside. After the paste has hardened the core removed and'a paste is applied to the inside of the body so formed. This method is, however, only possible with very thick wire and is not suitable for all the shapes of the bodies to be heated electric lly."

My invention relates to a method which crucible and form for making it,

vention.

then the wire spiral so formed The second method is also only possiedge of thematerial v with the upper part'of the fabric} is withthat the...platinum wire 4 with the g H upon a little heated, so as States Patent N o. 688,170,is as follows: The

renders it possible'to produce in a simple and easy manner crucibles, boxes, inuflles, plates, and other bodies almost of all possible shapes in which even very thin platinum wire is safely'embeddedr In the accompanying drawing, Figure 1 is a vertic al section of a crucible embodying the invention. Fig. 2 is a vertical section of a Fig. '3'is a vertical section of a modification of the in- The new method is as follows: For produclng aicrucible c,-say of the shape shown in a vertical section at Fig. 1', a form 1' of a corresponding shape (see Fig. 2) and preferably rovided with a knob or handle 2 is covered up to its neck with a fabric or net of organic fibers tightened on it or sewed-together, or a knitted stocking 3 of organic material may be I drawn over the form 1 and may be secured on it by means of twine or the like tightened round its neck. Next a-platiinim wire 4 is wound spirally, as shown, or' placed in a zig zag line on the cover 3, and is thereon sewed with thread or yarn 5.. with a hole 10 for the wire '51, maybe internally lined with a fireproof insulating mate A form 6, provided rial 7such as clay, porcelain, fire-clay, or the like.-and the form l covered with the fabric 3, and the platinum wire may be pressed" into the material 7, so that theflatt'er fills up the space between the two forms '1 'and 2,-or the insulating material 7 maybe formed or cast on the form 1 in the form 6. When the? material 7 has hardened by drying, the'fab;

ric 3' orthe like is drawn, so 7 ower part-of the fabric 301' the like is leftbe-g cut through stroundthe 7 and the internal form 1 hind in the body 7 now formed. Then the external form 6 is in'any known manner removed from the body 7 The latteris there I;

to destroy'theorganic fabric 3 or the like by burnipg it. e bo'dyis now internally lined in any known? manner with the same insulating material, so as to form the crucible. Y 4 1.) 'Where so preferred, this'crucibie may be enameled. Atla'st the.

high temperature, use. The forms 1 (Shownat Fig,

crucible is finished in the usual manner by burning it ata when it will be ready" for and 2 may beof wood,

sulating material, allowing the latter 'harden, cutting off the fatric acove the metal, or any other suitable material. Of course the platinum wire l may he replaced by a thin strip of platinum, which is spirally wound or placed in a zigzag; linethe same as before, if so desired. For lalgeifijve *ls the wire 4 is preferalzly replaced by who net. Vessels of any other shape may he produced in the manner described aizo e. Other bodies adapted to be heated electrically may heproduced ina similar manner.

What I claim as my invention, and desire to secure by Letters latent, is-- 1. The hereindescril:ed method of pro ducing bodies to lie heated electric-ally, which consists in securing aresistanc in the desired position ly means of organic matter, applying a layer of fireproof insulating; mate rial to the one side of the resistame, allow-- ing this layer to harden, heating it a little to destroy the organic matter, applyi' a second layer of fireproqf insulating n 'erial to the other side of the resistance, alliHVlIl J: the second layer to harden, and fllllSllll'lg the body by turning it at a high temperature.

2. The herein-(les -rilted method of producing vessels to he heated electrically, which consists in covering an internal form with a fabric of or anic material, securing a resistance (wire, strip or wire net) in the desired position on the fabric by sewing" it thereon with yarn of organic filler, introducing the internal form with the falnit and the resistance into an external form, filling up the space between them with a fireproof inexternal form, withdrawing the internal form with the rest of fabric, removing the external form, heating a little the vessel so for ied to destroy the organic matter, applying a layer of fireproof insulating material to the inside of the vessel, allowing this second layer to harden, and :tinisl 119* the body by burning it at a high temperature.

3. T he herein-descrihed method of produ iing ltodies to he heated electrically, white consists in. securing a resistance in the desired position by means of organic matter, ap ivlying a layer of fireproof insulating mate-- rial to the one side of the resistance, allowing this layer to harden, heating it a little to destroy the organic matter, applying a second layer of fireproof insulating material to the other side of the resistance, allowing the second layer to harden burning the body at a high temperature, and enameling it.

4:. The herein-described method of producing vessels to he heated electrically, which consists in covering an internal form with a faltric of organic material, securing a resistan e sired position on the fabric by sewing; it thereon wit h yarn of organic liher, introduc log the internal form with the fabric and the resists-me into an external form, filling up 'e heti'veen them with a fireproof in sulating material, allowing the latter 'to harden, cutting oil the fabric altove the external form, withdrawing the internal form with the rest. of fahrie, removing the external form, heating a little the vessel so formed to destroy the organic matter, applying a layer of fireproof insulating material to the inside of the vessel, allowing this second layer to harden, burning the hody at a high temperature, and enameling it.

in testimony whereof I have signed my name to this specification in the presence of two snlisorihing' witnesses.

, EST I-IAAGN.

ilitnesses: V

FRANZ HASSLACH'ER, EPXYDZ DIPPEL.

(wire, strip or wire net) in the de- 

